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Growth Inhibition of Chicks on Rations Containing Corn Grits*
Growth Inhibition of Chicks on Rations Containing Corn Grits* P. S. SARMA AND C. A. ELVEHJEM Department of Biochemistry, College of Agriculture, University of Wisconsin, Madison (Received for publication, July 20, 194S)
I
The purified rations used in these experiments consisted of dextrin, alcoholextracted casein, gelatin, soybean oil,
Day old White Leghorn chicks were divided into groups of six and placed in electrically heated cages with raised screen bottoms. The growth was studied over a period of four weeks. The average of the final weights of the chicks and also the average gain in weight per week are given in the table. It will be seen from the results that the addition of corn grits decreased the
* Published with the approval of the Director of the Wisconsin Agricultural Experiment Station. This work was supported in part by a grant from the Wander Company, Chicago, Illinois. We are indebted to Merck and Company, Inc., Rahway, New Jersey for the generous supply of crystalline B vitamins and to Wilson Laboratories, Inc., Chicago, Illinois for liver extract. 39
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salts V (Briggs et al. 1943) and cystine in the proportions listed in Table 1. The composition of the different diets varied chiefly in their protein content and in the amount of nicotinic acid added. The corn rations contained 40 gm. of corn grits in every 100 gm. of the diet, while the rations without corn grits served as controls. Since corn grits contained only 9% protein (NX6.25), as determined by crude protein analysis, the casein content of the rations was adjusted so that the corn ration and the control ration contained the same amount of total protein. The amount of salts V and soybean oil were also adjusted to make the rations as nearly like as possible. All the diets contained per 100 gm. the following amounts of vitamins—thiamin 0.3 mg.; riboflavin 0.6 mg.; pyridoxin 0.4 mg.; calcium pantothenate 1.5 mg.; choline chloride 150 mg.; inositol 100 mg.; 2-methyl, 1-4 naphthoquinone 0.5 mg.; biotin 0.015 mg.; norite eluate fraction^5 gm. solubilized liver (Mills et al. 1942) and a-tocopherol 0.3 mg. Every chick received three drops of a vitamin A and D concentrate once a week.
T HAS been shown in previous studies (Krehl et al. 1945a, b) that corn or corn grits when added to a nicotinic acid low ration markedly inhibited the growth of rats and that this deleterious effect was completely counteracted by the addition of either nicotinic acid or tryptophane to the diet. Further, in studies with dogs, it was found that the animal's requirement for nicotinic acid was considerably increased when corn grits was present in the purified ration (Krehl et al. 1945c). It was therefore of interest to determine whether corn grits exerted a similar effect in other species particularly in chicks. The chick requires a dietary source of nicotinic acid for optimal growth and for the prevention of chick blacktongue; a minimum level of 1.8 mg. per 100 gm. of ration is needed for this purpose (Briggs et al. 1942). In this paper, results are presented to show that the addition of corn grits to a purified diet containing sub-optimal levels of nicotinic acid reduced the growth rate of chicks and that this inhibition was overcome by additional amounts of nicotinic acid in the diet.
40
P. S. SARMA AND C. A. ELVEHJEM TABLE 1.—Composition of diets and growth response
Composition of diet
1
Dextrin, gm. 65.0 Alcohol-extracted case14.6 in, gm. 10.0 Gelatin, gm. 4.2 Soybean oil, gm. 6.0 Salts Y, gm. 0.3 Cystine, gm. Corn grits, gm. — Nicotinic acid added in 0.5 mg.
2
3
4
5
6
7
31.0
31.0
63.6
29.6
29.6
11.0 10.0 3.0 5.0 0.3 40.0
11.0 10.0 3.0 5.0 0.3 40.0
16.0 10.0 4.2 6.0 0.3
12.4 10.0 3.0 5.0 0.3 40.0
0.5
1.5
— 0.75
0.75
.
8
9
61.6
27.6
27.6
12.4 10.0 . 3.0 5.0 0.3 40.0
18.0 10.0 4.2 6.0 0.3
—
14.4 10.0 3.0 5.0 0.3 40.0
14.4 10.0 3.0 5.0 0.3 40.0
1.75
0.5
0.5
1.5
28.0
28.0
Total protein in the diet, 24.6 1.05
24.6 2.05
26.0 1.05
26.0
26.0
28.0
1.3
2.3
0.8
1.05
2.05
77
147
143
94
162
118
83
178
6
24
23
12
29
18
9
32
growth to nearly half that which was obtained on the control ration, and this decrease in growth was observed at all the three levels of protein and nicotinic acid. The marked growth inhibition occurred even though the corn rations contained more nicotinic acid than those without corn grits. However, the addition of 1 mg. of nicotinic acid to 100 gm. of corn grits rations successfully counteracted this growth retarding effect and the growth of chicks was greater than on the control rations. The growth inhibition observed in chicks on a corn grits ration and the counteraction by nicotinic acid is similar to that observed in rats (Krehl etal. 1945a). In commercial feeding of poultry, the presence of an adequate amount of nicotinic acid in the diet is therefore of great importance, especially when corn constitutes a major portion of the feed. A good average chick ration will generally contain enough nicotinic acid to counteract the deleterious effect of corn. However, it is important to determine the actual amount of nicotinic acid present. Summary. Corn grits when added to a purified ration to the extent of 40%
exerted a deleterious effect on the growth of chicks. This growth retardation was observed at three different levels of protein. In all cases this untoward effect of corn was completely counteracted by the addition of nicotinic acid to the ration. REFERENCES
Krehl, W. A., L. J. Teply, and C. A. Elvehjem, 1945a. Corn as an etiological factor in theproduction of a nictonic acid deficiency in the rat. Science 101: 283. Krehl, W. A., L. J. Teply, P. S. Sarma, and C. A. Elvehjem, 1945b. Growth retarding effect of corn in nicotinic acid-low rations and its counteraction by tryptophane. Science 101: 489-490. Krehl, W. A., L. J. Teply, and C. A. Elvehjem, 1945c. Effect of corn grits on nicotinic acid requirements of the dog. Proc. Soc. Exp. Biol, and Med. 58:334-337. Briggs, G. M., Jr., R. C. Mills, C. A. Elvehjem, and E. B. Hart, 1942. Nicotinic acid in chick nutrition. Proc. Soc. Exp. Biol, and Med. 51: 59-61. Briggs, G. M., Jr., T. D. Luckey, C. A. Elvehjem, and E. B. Hart, 1943. Studies on two chemically unidentified water-soluble vitamins necessary for the chick. J. Biol. Chem. 148:163-172. Mills, R. C , G. M. Briggs, Jr., C. A. Elvehjem, and E. B. Hart, 1942. Lactobacillus casei « factor in the nutrition of the chick. Proc. Soc. Exp. Biol, and Med. 49: 186-189.
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24.6 e^-% . . Total nicotinic acid in 0.8 the diet mg. % Average weight of chicks 103 after 4 weeks, gm. Average weekly gain in weight of the chicks, 13 gm.
I
The purified rations used in these experiments consisted of dextrin, alcoholextracted casein, gelatin, soybean oil,
Day old White Leghorn chicks were divided into groups of six and placed in electrically heated cages with raised screen bottoms. The growth was studied over a period of four weeks. The average of the final weights of the chicks and also the average gain in weight per week are given in the table. It will be seen from the results that the addition of corn grits decreased the
* Published with the approval of the Director of the Wisconsin Agricultural Experiment Station. This work was supported in part by a grant from the Wander Company, Chicago, Illinois. We are indebted to Merck and Company, Inc., Rahway, New Jersey for the generous supply of crystalline B vitamins and to Wilson Laboratories, Inc., Chicago, Illinois for liver extract. 39
Downloaded from http://ps.oxfordjournals.org/ by guest on May 19, 2015
salts V (Briggs et al. 1943) and cystine in the proportions listed in Table 1. The composition of the different diets varied chiefly in their protein content and in the amount of nicotinic acid added. The corn rations contained 40 gm. of corn grits in every 100 gm. of the diet, while the rations without corn grits served as controls. Since corn grits contained only 9% protein (NX6.25), as determined by crude protein analysis, the casein content of the rations was adjusted so that the corn ration and the control ration contained the same amount of total protein. The amount of salts V and soybean oil were also adjusted to make the rations as nearly like as possible. All the diets contained per 100 gm. the following amounts of vitamins—thiamin 0.3 mg.; riboflavin 0.6 mg.; pyridoxin 0.4 mg.; calcium pantothenate 1.5 mg.; choline chloride 150 mg.; inositol 100 mg.; 2-methyl, 1-4 naphthoquinone 0.5 mg.; biotin 0.015 mg.; norite eluate fraction^5 gm. solubilized liver (Mills et al. 1942) and a-tocopherol 0.3 mg. Every chick received three drops of a vitamin A and D concentrate once a week.
T HAS been shown in previous studies (Krehl et al. 1945a, b) that corn or corn grits when added to a nicotinic acid low ration markedly inhibited the growth of rats and that this deleterious effect was completely counteracted by the addition of either nicotinic acid or tryptophane to the diet. Further, in studies with dogs, it was found that the animal's requirement for nicotinic acid was considerably increased when corn grits was present in the purified ration (Krehl et al. 1945c). It was therefore of interest to determine whether corn grits exerted a similar effect in other species particularly in chicks. The chick requires a dietary source of nicotinic acid for optimal growth and for the prevention of chick blacktongue; a minimum level of 1.8 mg. per 100 gm. of ration is needed for this purpose (Briggs et al. 1942). In this paper, results are presented to show that the addition of corn grits to a purified diet containing sub-optimal levels of nicotinic acid reduced the growth rate of chicks and that this inhibition was overcome by additional amounts of nicotinic acid in the diet.
40
P. S. SARMA AND C. A. ELVEHJEM TABLE 1.—Composition of diets and growth response
Composition of diet
1
Dextrin, gm. 65.0 Alcohol-extracted case14.6 in, gm. 10.0 Gelatin, gm. 4.2 Soybean oil, gm. 6.0 Salts Y, gm. 0.3 Cystine, gm. Corn grits, gm. — Nicotinic acid added in 0.5 mg.
2
3
4
5
6
7
31.0
31.0
63.6
29.6
29.6
11.0 10.0 3.0 5.0 0.3 40.0
11.0 10.0 3.0 5.0 0.3 40.0
16.0 10.0 4.2 6.0 0.3
12.4 10.0 3.0 5.0 0.3 40.0
0.5
1.5
— 0.75
0.75
.
8
9
61.6
27.6
27.6
12.4 10.0 . 3.0 5.0 0.3 40.0
18.0 10.0 4.2 6.0 0.3
—
14.4 10.0 3.0 5.0 0.3 40.0
14.4 10.0 3.0 5.0 0.3 40.0
1.75
0.5
0.5
1.5
28.0
28.0
Total protein in the diet, 24.6 1.05
24.6 2.05
26.0 1.05
26.0
26.0
28.0
1.3
2.3
0.8
1.05
2.05
77
147
143
94
162
118
83
178
6
24
23
12
29
18
9
32
growth to nearly half that which was obtained on the control ration, and this decrease in growth was observed at all the three levels of protein and nicotinic acid. The marked growth inhibition occurred even though the corn rations contained more nicotinic acid than those without corn grits. However, the addition of 1 mg. of nicotinic acid to 100 gm. of corn grits rations successfully counteracted this growth retarding effect and the growth of chicks was greater than on the control rations. The growth inhibition observed in chicks on a corn grits ration and the counteraction by nicotinic acid is similar to that observed in rats (Krehl etal. 1945a). In commercial feeding of poultry, the presence of an adequate amount of nicotinic acid in the diet is therefore of great importance, especially when corn constitutes a major portion of the feed. A good average chick ration will generally contain enough nicotinic acid to counteract the deleterious effect of corn. However, it is important to determine the actual amount of nicotinic acid present. Summary. Corn grits when added to a purified ration to the extent of 40%
exerted a deleterious effect on the growth of chicks. This growth retardation was observed at three different levels of protein. In all cases this untoward effect of corn was completely counteracted by the addition of nicotinic acid to the ration. REFERENCES
Krehl, W. A., L. J. Teply, and C. A. Elvehjem, 1945a. Corn as an etiological factor in theproduction of a nictonic acid deficiency in the rat. Science 101: 283. Krehl, W. A., L. J. Teply, P. S. Sarma, and C. A. Elvehjem, 1945b. Growth retarding effect of corn in nicotinic acid-low rations and its counteraction by tryptophane. Science 101: 489-490. Krehl, W. A., L. J. Teply, and C. A. Elvehjem, 1945c. Effect of corn grits on nicotinic acid requirements of the dog. Proc. Soc. Exp. Biol, and Med. 58:334-337. Briggs, G. M., Jr., R. C. Mills, C. A. Elvehjem, and E. B. Hart, 1942. Nicotinic acid in chick nutrition. Proc. Soc. Exp. Biol, and Med. 51: 59-61. Briggs, G. M., Jr., T. D. Luckey, C. A. Elvehjem, and E. B. Hart, 1943. Studies on two chemically unidentified water-soluble vitamins necessary for the chick. J. Biol. Chem. 148:163-172. Mills, R. C , G. M. Briggs, Jr., C. A. Elvehjem, and E. B. Hart, 1942. Lactobacillus casei « factor in the nutrition of the chick. Proc. Soc. Exp. Biol, and Med. 49: 186-189.
Downloaded from http://ps.oxfordjournals.org/ by guest on May 19, 2015
24.6 e^-% . . Total nicotinic acid in 0.8 the diet mg. % Average weight of chicks 103 after 4 weeks, gm. Average weekly gain in weight of the chicks, 13 gm.